More on that here: https://en.wikipedia.org/wiki/Watts_Bar_Nuclear_Plant#Unit_2

Here's some context for what was happening in 1985, from the eia:

>"As a consequence of the identification of a large number of deficiencies shortly before the WBN Unit 1 license was expected to be issued, the Nuclear Regulatory Commission (NRC) sent a letter to TVA [...]. In response to this letter, TVA developed a Nuclear Performance Plan (NPP) to address corporate and site-specific issues, establishing programs to address a wide variety of material, design, and programmatic deficiencies. WBN Unit 2 construction was suspended at about that time, with major structures in place and equipment such as reactor coolant system piping installed."

And while most of the documentation was very terse and spoke more about specific regulatory requirements that I don't understand, this is pretty interesting:

(From the nrc.gov)

>"The NRC staff reviewed TVA’s refurbishment program and found the following: (1) TVA was refurbishing or replacing most active components and instruments; (2) TVA had determined the potential degradation mechanism for each category of components, along with any contributing environmental factors; (3) the acceptance criteria were developed from the licensing basis, design specifications, and vendor specifications; (4) the proposed inspections and testing included in the program could be expected to identify degradation; and (5) refurbishment activities would be in accordance with applicable vendor and design specifications or requirements."

That sounds like a massive, massive amount of work. It explains why it took longer even if the reactor was apparently 60% completed.

(From the eia) :

>"That time, a study found Unit 2 to be effectively 60% complete with $1.7 billion invested. The study said the plant could be finished in five years at an additional cost of $2.5 billion"

One of the bullets on the box is that the AP1000 uses a fairly standardized design, unlike many prior designs which were mostly a patchwork of one-off designs. The AP1000 still being "in production" means parts are available.

I was wondering how that was powered.

That seems to be common with nuclear power plants. The latest one near where I live (Angra 3) has been under construction since 1984, and it should be complete in a few more years if it doesn't pause again; construction of the previous one (Angra 2), according to Wikipedia, started in 1976 and came online in 2001.

https://en.wikipedia.org/wiki/Three_Mile_Island_accident

Like a car crash where the seat belts and airbags lead to no injuries.

And then all driving was banned.

[1] - https://en.wikipedia.org/wiki/Three_Mile_Island_accident_hea...

Statistically it's inconclusive whether slight increases in some zones from a bit below average to a bit above average cancer rates is linked to TMI or to stress and|or increased screening.

What is certain, beyond a doubt, is that within the last week an explosion at a nickel plant in Indonesia left at least 13 dead and 46 injured.

https://www.theguardian.com/world/2023/dec/24/explosion-at-a...

That's an example of the generally unreported and ongoing human cost of battery technology.

Note Well: I'm not pro nuclear OR anti battery - I am pragmatic about the real consequences of resource mining and extraction having been part of exploration geophysics and global resource mapping for several decades.

After the cooling water began to drain out of the broken pressure valve on the morning of March 28, 1979, emergency cooling pumps automatically went into operation. Left alone, these safety devices would have prevented the development of a larger crisis. However, human operators in the control room misread confusing and contradictory readings and shut off the emergency water system. The reactor was also shut down, but residual heat from the fission process was still being released. By early morning, the core had heated to over 4,000 degrees, just 1,000 degrees short of meltdown. In the meltdown scenario, the core melts, and deadly radiation drifts across the countryside, fatally sickening a potentially great number of people.

As the plant operators struggled to understand what had happened, the contaminated water was releasing radioactive gases throughout the plant. The radiation levels, though not immediately life-threatening, were dangerous, and the core cooked further as the contaminated water was contained and precautions were taken to protect the operators. Shortly after 8 a.m., word of the accident leaked to the outside world. The plant’s parent company, Metropolitan Edison, downplayed the crisis and claimed that no radiation had been detected off plant grounds, but the same day inspectors detected slightly increased levels of radiation nearby as a result of the contaminated water leak. Pennsylvania Governor Dick Thornburgh considered calling an evacuation.

Finally, at about 8 p.m., plant operators realized they needed to get water moving through the core again and restarted the pumps. The temperature began to drop, and pressure in the reactor was reduced. The reactor had come within less than an hour of a complete meltdown. More than half the core was destroyed or molten, but it had not broken its protective shell, and no radiation was escaping. The crisis was apparently over.

https://www.history.com/this-day-in-history/nuclear-accident...

Two decades isn't very long for an infrastructure project, which is unfortunate since long-term planning benefits greatly from political stability, and many areas are seeing large shifts for the worse in that regard.

an abandoned nuclear station in Cuba

https://news.ycombinator.com/item?id=35672840

https://en.wikipedia.org/wiki/St._Barbara%27s_Church,_Kutn%C...

was under construction from 1970. I believe it's had 3 generations working on it.

*excluding research or military reactors of course.

Edit: Tried to edit the edit but somehow deleted the rest of the edit. It was something to the tune of how a big problem with renewables is the fact that peak solar production does not match peak energy consumption, and storage is very difficult, so realistically we'll need a wide variety of energy options to fully transition to renewables. Nuclear is reliable and to some degree adjustable, helping to alleviate the storage issue. Basically, it's my opinion that nuclear works well with other renewable sources, and a full renewable transition will certainly involve more of it.

Does the US have more 50cm^3 sized blocks of U235, or more square kilometers of land with low land values and high annual insolation?

There's an estimated 6 million tonnes of mineable uranium reserves in the world [0]. Of which 0.72% is U-235, so we have a worldwide reserve of 43200 tonnes, or 43.2 million Kg U-235.

Arizona is about 300k square kilometers. If we covered an area 10% the size of Arizona in solar panels, then they would have produced more energy than all the world's known U-235 in just four years. And would continue producing after those four years are up.

[0] https://world-nuclear.org/information-library/nuclear-fuel-c...

https://en.wikipedia.org/wiki/Uranium_in_the_environment

>> Uranium is a naturally occurring element found in low levels within all rock, soil, and water. This is the highest-numbered element to be found naturally in significant quantities on earth. According to the United Nations Scientific Committee on the Effects of Atomic Radiation the normal concentration of uranium in soil is 300 μg/kg to 11.7 mg/kg. ... It is considered to be more plentiful than antimony, beryllium, cadmium, gold, mercury, silver, or tungsten and is about as abundant as tin, arsenic or molybdenum.

How uranium ore becomes fuel rods: (Actually a rather simple process imho.)

https://youtu.be/9x7DozCqLxU

https://youtu.be/c7ehyxRBMbw

https://www.tiktok.com/@nuclearsciencelover/video/7092135813...

Fuel costs are 10% of the cost of nuclear electricity. The vast majority is financing.

The financing for nuclear is expensive primarily because:

1) The costs of construction are so high - so huge amounts of financing needed.

2) The amount of time before investors see any ROI is very long.

A long time ago, when electricity markets were fully monopolized end to end, the long-term ROI on nuclear and other generating assets was guaranteed by the government, and the financial risk was borne by society.

Now, electricity markets have been liberalized (at least at the generation level). Simultaneously, far less capital-intensive generation technologies have been created (renewables, combined-cycle gas, and increasingly storage). These technologies provide an earlier ROI for risk-averse capitalists.

> Why do people bother mining it?

> Because mining it is relatively cheap.

Something does not add up here.

(Though I have no real opinion on whether seawater extraction really is just as good...somewhat dubios)

https://whatisnuclear.com/nuclear-sustainability.html

Not much different than most HN comments which 90% of the time are only one or two sentences.

For what it’s worth, the cost to extract uranium from seawater is actually a very complicated subject. It is generally cited that the cost is approximately 2x the mining cost, but that’s based on estimates for seawater extraction.

https://www.researchgate.net/publication/280745206_Cost_Esti...

And the same is true for solar. In fact, a growing number of agro-voltaic projects are seeing a net positive on crop yields from solar panels due to the increased shading and decreased temperatures.

"Austin-Bergstrom International Airport (AUS) and Austin Energy celebrate the completion of a new solar panel array constructed on the AUS campus that will produce 1.8 megawatts of locally-generated, renewable energy. ... With 6,642 solar panels spanning across a distance that is equal size to two football fields, the array on the top floor of the airport’s Blue Garage is the largest on-site renewable energy installation on the AUS campus. The panels offer shaded parking for Blue Garage customers and will generate enough solar energy to power up to 160 homes per year."

[0] https://www.austintexas.gov/news/austin-bergstrom-internatio...

“Combining two usage modes based on Insolight’s optical micro-tracking technology, these modules focus light on high-efficiency solar cells,” Insolight said in a press release. “When aligned, the optical system can generate energy (E-MODE), but it is also possible to unalign it to ‘leak’ the light (MLT-MODE). The solar modules therefore act like a ‘smart’ shade adjusting the amount of light they let through.”

This makes it possible to optimize the photosynthesis of plants during the seasons and reduce the negative impact of high summer heat on the yields and quality of agricultural products, while recovering the rest of the light in the form of electricity. Starting from July, the panels will be tested for four years on a 165-square-meter surface area. They will replace protective plastic tunnels on strawberries and raspberries.

“Dynamically adjusting the light transmitted to the plants paves the way for increased protection from climate variations and possible increases in crop yields thanks to the matching of the light to the needs of the plants and the lowering of the temperature during heat waves via the shading effect,” said Bastien Christ, head of the berries and medicinal plants group at Agroscope.

A similar project using different module technology: https://www.pv-magazine.com/2023/10/31/baywa-re-starts-build...

The fact is that agrivoltaics has been very successful, for reasons you probably would not guess in a wholesale void of facts. Looking up the facts, you could actually learn something.

This is a linked graph of solar growth compared to International Energy Agency's World Energy Outlook predictions: https://rameznaam.com/wp-content/uploads/2020/05/IEA-Solar-G...

In each of 2006, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2018, the IEA predicted deployment of solar would stop accelerating (line going up) and steady off into consistant growth (flatline on that graph). Every year they have been very quickly wrong, and the 2019 predition of flatline is so wrong that by 2021 actual production of 190GW was WAYYYY off the top of that chart. At this rate we may not need to figure out storage nearly as much as we think.

> "What people have missed is that reaching cost parity on fuel synthesis will unlock huge new demand centers [and trigger an acceleration in demand/investment/research/cost decline of solar created synthetic fuels]."

[1] https://news.ycombinator.com/item?id=32197012 (article rather than comments)

https://news.ycombinator.com/item?id=37218727

I think what you mean is that wind alone is not baseload, not that it is unreliable. It is quite reliable in that its availability is predictable such that it can be coordinated with storage to create virtual baseload. Therefore its failure modes are relatively mild in impact.

In contrast, large centralized plants (whether combustion or nuclear) have far more consequential failure modes - for example, losing 1GW of power with little notice, as can happen with these plants, is usually a grid emergency event.

> Hydrostor, which is based in Toronto, is one of several startups working on fixing those problems. The company says it’s figured out a way to capture and reuse the heat generated when air is compressed, eliminating the need to burn gas. It’s also figured out a way to make the mechanics work in areas where caverns must be dug out of hard rock, rather than salt.

https://www.latimes.com/environment/newsletter/2023-01-12/th...

This first thing we need to do is align the costs and incentives. What I mean by that is simply allow the market, or government, to dictate the real cost of providing electricity at night. If there are no solar panels (nighttime), and whatever grid-scale batteries are available cost 1$/kwh then so be it, charge that amount to the consumer. People will learn to forego "bathing" in electricity at night endlessly. For decades we've been spoiled with ridiculous "energy on a tap" that just gives us oodles at the flick of a switch, and we just need to take that away.

As a side-effect of this whole "switching off the endless tap", micro-grids are the future. Small communities with mini-grid-scale batteries and sharing of electricity will take over this stupid "national synchronized grid" idea that has gimped our ability to be agile wrt local energy generation.

I take it you live somewhere warm in the winter. We are already looking at removing other heating options like propane and natural gas furnaces, coal and oil heating is mostly phased out, and burning wood isn't great for the environment either. So electrical heating is necessary anywhere where its normal to freeze for several months. Telling people to stop bathing in electricity at night when that what keeps them alive is bullshit.

"micro-grids are the future. Small communities with mini-grid-scale batteries and sharing of electricity will take over this stupid "national synchronized grid" idea that has gimped our ability to be agile wrt local energy generation."

Why don't you ask Texas residents how not being part of the national synchronized grid worked out for them 2 years ago?

You heat your home up during the day and evening, and as you retire for the night it's switched off. With sufficient insulation and warm bedding you don't need active heating overnight.

So it's absolutely compatible with an electric supply that's heavily biased towards the daytime.

I live around 60 latitude and here during the winter it might not be even that cold (tho it can be -20 or -30C).

It’s that the amount of sunshine and the angle it shines at means that for about 3 months the PV production is essentially zero.

This is during the time the demand is highest.

This seems like the quintessential example of some Cali tech bro nor understanding that there is anyone outside of their little bubble and assui everyone just lives like them.

There are people outside everbodies particular bubbles.

I never said anything of the sort. You're taking a really bad-faith and extreme straw-man of what I said, and I refuse to participate.

Surface wind is not reliable. I've seen proposals to put turbines on large kites or gliders tethered to the ground. There's pretty much always strong winds over most of the United States somewhere between the surface and 10000 feet.

Also, a failure scenario would mean tonnes of windmill crashing down from high altitude. Hmmmmm

10000 feet is less than 2 miles. Even in high winds it wouldn't get more than a a couple or miles or so before hitting the ground.

There are plenty of places in the US where you could fly where it would be centered over a 6 mile diameter circle that contains no people or valuable buildings except for people and buildings that are part of the power facility.

Also, solar panels don't need any land. There are so many places we can install solar without 'consuming' land. They can be roofs, floating on tops of lakes and reservoirs with the added benefit of preventing evaporation, agrivoltaics combined with farmland, vertical panels, superfund sites, deserts, along the highways, etc.

There is enough Uranium on the planet for a few centuries. Make it a few millennia if you breed it, and lots and lots of millennia if you expand your reactors to use other fuels. But most of it is way more expensive to get than what we use today... what actually makes very little difference for the final costs.

Technically you need to factor in the fact that a nuclear plant can be built relatively near the places where its power will be consumed; some mass of solar power in Nevada is highly inefficient for powering New York or Virginia, even if you built HVDC lines to cut down on total line losses, so you'll need to pick land tracts reasonably near battery banks that would in turn be near cities.

Is there something about Ohio that means they have no atmospheric wind nor natural sunlight?

Would covering a desert in solar panels cause more thermal solar absorption in that area than would otherwise happen? Yes.

But if we're optimizing for "offsetting the heating effect of human GHG emissions", then installing 4.5TW of solar (about 4x what has been installed worldwide to date) would have a much more positive effect.

The world currently has 1.1TW of solar installed, producing about 6% of all electricity. So our new installation would be on its own capable of supplying 25% of global electricity usage. The corresponding drop in GHG emissions from the shutdown of coal, gas, and oil power plants would far outweigh the fact that part of the desert has been turned black.

In theory, darkening a portion of the Earth with high albedo (snow, sand) is worse than darkening a portion of the Earth with low albedo (roads, roofs, forest). Then it should be better to use a greener area for solar panels so long as the capacity factors would be similar.

And what are the various Friends of Rare Bugs and Small Furry Animals groups doing in the meantime?

I joke, but even I would balk at the environmental impact of that. Certainly it's going to be greater than any equivalent nuclear installation.

> Of which 0.72% is U-235

Fortunately we're not limited to U-235. With breeder reactors, there's enough nuclear fuel to run human civilization for billions-with-a-b of years.

[1] https://www.archdaily.com/976069/when-5-percent-of-the-unite...

The people who will be screaming about covering the desert with solar panels are exactly the same people who scream about covering the land with car parks.

Exactly.

The only energy source radical environmentalists like is one that exists only in a fantasy. As soon as it starts being built, it becomes evil.

Note that they're already up in arms about windmills killing birds.

Also, covering the desert is definitely going to change the local environment. At a minimum, every joule that goes into the power transmission lines is a joule that will not be available for use by the desert ecosystem.

That's missing the huge and expensive nuclear power plant around that kilogram of uranium.

If you don't account for the conversion device (for which solar is cheaper per GJ than nuclear power plants), then light is a much better medium: assuming 15% efficiency, which is a conservative estimate, solar panels can convert one kilogram of solar light (remember e=mc^2) into 13.5 terajoules of electricity.

https://www.wolframalpha.com/input?i=1+kg+*+c%5E2+*+15%25+in...

The sun bombards our planet with around 61 metric tons of light per day:

https://www.wolframalpha.com/input?i=2+*+pi+*+radius+of+eart...

Where the 6 kwh/m^2 come from: https://en.wikipedia.org/wiki/Solar_irradiance#Irradiance_on...

Any chance you could help compare the construction cost of this nuclear plant to another recently constructed solar or wind farm measured against... I guess capacity?

Given the intermittent nature of solar/wind, does capacity even make sense to compare in a context without supporting batteries?

I'll give it a shot but I am probably super wrong.

** Nuclear:

I'll use the plant from the article https://en.wikipedia.org/wiki/Vogtle_Electric_Generating_Pla...

Construction costs 18b USD (does that include loans?)

Nameplate capacity of 2302MW

Used capacity is 91% so 2094MW

$18b / nameplate capacity = $7.8 USD per rated W

$18b / used capacity = $8.60 per realized W

** Solar (excluding batteries):

I picked a relatively large, recent, US based solar farm from the list of plants in wikipedia

Agua Caliente Solar Project (2016) https://en.wikipedia.org/wiki/Agua_Caliente_Solar_Project

Construction costs 1.8b USD

Nameplate capacity of 290 MW

Used capacity is 28% so 81 MW

$1.8b / nameplate capacity = $6.2 USD per rated W

$1.8b / used capacity = $22 USD per realized W (that can't be right?)

** Note:

I don't know if my math is right, I don't know if the costs factor in loans, also the nameplate capacity for the nuclear plant is MWe and the solar plant is MWac so I am unsure how that works out.

I found mention of a bond issuance and someone purchasing the project here [2]. If it’s $1b, then it’s $5.26. If $2b then $10.53.

So they’re in the same ballpark. But one type of plant runs 20-30 years and the other for 50-80 years @ 90% capacity factor. The CANDU reactors are especially cool in that they can use natural uranium and refueled without a shutdown [3].

—- [1] - https://en.m.wikipedia.org/wiki/Solar_Star [2] - https://www.sustainablebusiness.com/2013/06/1-billion-bond-o... [3] - https://energyeducation.ca/encyclopedia/On-line_refueling_of...

> Agua Caliente Solar Project (2016)

Note that solar being cheaper than nuclear is a more recent phenomenon than 2016. The solar panel prices went from $0.63 to $0.26 in the time span between 2016 and 2022.

https://ourworldindata.org/grapher/solar-pv-prices?time=2002...

A better example is Spotsylvania Solar/Highlander Solar: https://www.sheppardmullin.com/assets/htmldocuments/PFI%2020...

Construction costs: $905m USD

Nameplate capacity: 618 MW

I couldn't find used capacity factors but Yuma is one of the sunniest counties in the USA while Spotsylvania county is further north and also has less sunny days. With an assumed capacity factor of 18%, one gets 111 MW.

$905m / nameplate capacity = $1.48 USD per rated W

$905m / used capacity = $8.24 USD per realized W

I'm certain nuclear running costs would dwarf solar - I think solar just needs fresh water, cleaning and hardware maintenance (replacing inverters, and such).

Would be interesting to work the running costs into the "$ per realized W" calculation.

I'd also like to see how battery-backed solar compares. I assume the objective would be to solve the intermittency issue, but I am hopeful it would increase the capacity factor as well.

Another thing that's interesting to consider is multi-purpose energy utilization you get with nuclear - like desalination and hydrogen generation - though the latter is uneconomical because hydrogen produced from fossil fuels is much cheaper.

https://news.ycombinator.com/item?id=38303819

Self citing:

Better not use biased opinion pieces, when there numbers from government sources (US, but eho cares):

LCOE (total, incl. CAPEX, in USD per MWh):

coal 82.6, combined cycle 39.9, advanced nuclear 81.7, geothermal 37.6, biomass 90.1, onshore wind 40, offshore wind (that one was a surprise, since offshore wind should be quite cheap, mainly driven by capital cost of 104 USD per MWh) 105, solar 33.8, solar hybrid 49 and hydro 64.

Variable cost (same as above):

coal 23.7, combined cycle 27.7, adv. nuclear 10.3, geothermal 1.2, biomass 30, onshore wind 0, offshore wind 0, solar 0, solar hybrid 0, hydro 4.1

All number from here:

https://www.eia.gov/outlooks/aeo/pdf/electricity_generation...., page 9.

1) "Water batteries" - highly efficient (far more than the 'chemical' you are apparently referring to) & responsive

2) Methods for using 'renewables' to produce &/ support production of chemical fuels - with the added draw / potential goal of 'closing' the 'carbon cycle'

As to #2, one of the ideals that has been kicked around for decades is to do something like: use 'renewables' to sequester CO2 from the atmosphere and convert it into something like butanol, for example.

Now, last I was up-to-date on any of this sort of work (~10+ years ago), the economics were not favorable. Certain types of commodity chemical production with 'biological basis' (another type of renewable, typically) had much more favorable properties economically. And, indeed, you do see, for example, (thermo)plastic products made from chemicals like "PLA" increasingly. But, the "biofuels" concept is / was much more challenging, especially as "fracking" technology made great leaps etc.

Nuclear has its pros and cons - blanket disavowal is fatuous. Nevertheless, there are substantially more options, systems, technologies, etc. in development and production than are often discussed in too many of the pro-nuke(s) / no nuke(s) 'sniping' chains that have been prevalent in society & on the internet since I was a wee tyke myself.

are you referring to P2X? I think P2X is an awesome solution for existing infrastructure, but it's obviously not particularly efficient. I am excited about pumped storage as well, but my fear there is we'll run out of sites, and obviously the 80% efficiency is still not ideal.

By no means am I arguing nuclear is a one size fits all solution.

"Highly efficient" is very vague.

What matters here are the numbers:

W/$

J/$

% round trip losses

% losses per hour

Number of cycles before replacement needed

Response time

Do you have them?

Move to a mixture of wind, solar, geothermal, hydro, nuclear - whatever makes sense.

When the last coal powered plant is shut off in US, we should celebrate that as a day off for everyone.

how about we as a society finally fulfill the promise of power to cheap to meter that we were told back in nuclears golden age before the carbon industry start the smear campaign against nuclear.

The environmental Greens had a lot to do with the smear. Even recently, they were the ones who pushed for the shutdown of German nuclear power which ended up increasing German CO2 output.

That's temporary, soon that will go back down again

And trees. Clearcutting forests to make room for a solar panels just seems wrong, a Captain Planet style of evil. There are all sorts of places where the terrain just isnt suited.

Most of the US isn't wooded. I don't think a significant number of projects propose clear-cutting to build solar farms. I don't know where that came from.

Seriously, while a lot has been written about the need to update the grid and install more long distance transmission lines to support renewables, even with the current grid it makes much more sense to install wind and solar in locations where it is more efficient and then transmit the electricity elsewhere. In Texas, most of the wind farms are in West Texas hundreds of miles away from Houston, for example.

It's very common for utility-scale solar to use single-axis trackers (the panels move from pointing east to pointing west through the day), unlike small-scale solar which usually has fixed panels (normally pointing south or north depending on which hemisphere you're on). The gain from single-axis trackers is high enough and their cost is low enough (a single geared motor can move a whole row of panels) to make it cost-effective.

(I haven't, so far, seen any large photovoltaic solar power plant which uses two-axis trackers to really track the sun; but thermal solar power plants with a central tower need these two-axis trackers to aim each mirror at the correct angle.)

"But there are also other ways to boost the energy production of solar panels – such as by tilting them to follow the Sun's path in the sky, similar to the way young sunflowers follow the sun from east to west during the day. Tracking technology, which is already in use on some land based solar arrays, helps increase the overall electricity production, as the panels constantly adjust to face the Sun."

1) www.bbc.com/future/article/20221116-the-floating-solar-panels-that-track-the-sun

There is nothing innately wrong with over building renewable and storage, and a transmission network.

It's an argument about economics, not physics.

But that's averaged over the month, what about a run of December days with heavy cloud cover, misty foggy atmosphere, still air, maybe some Icelandic volcano soot in the atmosphere, what's the worst we'd have to plan for, and how much overprovisioning would that take?

[1] https://shkspr.mobi/blog/2013/02/solar-update/

They're also published as open data.

The dark and dreary days tend to be the ones with the most wind power. The tides around our coast are in constant motion.

But, the big challenge is still storage. Domestic solar panels provide 100% of our yearly electricity use. At the moment I can only store 4.8kWh of excess.

So we need to over provision and over store - hopefully both at the same time.

https://globalwindatlas.info/en

Edit: also, the economics are such that you rarely want to drop load from a nuclear plant unless it's offline or for system reasons. The fuel cost is negligible so you'd rather turn off your gas plant or lower the coal plant and save on those fuels.

From what I understand it's not a theoretical constraint, but mostly a lack of enough commercial interest for any other design. But it is what it is.

Nuclear reactors absolutely can vary their output to match demand, this is what France has been doing for 50+ years (and what Germany was doing before switching back to coal). It's not as reactive as coal/gas, but you can still vary within 30-100% of output power at a speed of 5% change per minute. Way more than enough to react to 1-day-ahead forecasted supply/demand, and way more than enough to react minute-by-minute if you've got a tiny bit of storage to stabilize the grid's frequency (e.g. pumped hydro).

Ramping once is easy. Ramping continuously through the entire fuel cycle requires a meticulously planned fleet.

Thermally it is difficult to dial a reactor up and down. Generally the way nuclear power is modified is by not-sending the steam to generators through a by-pass and quenching their heat in some fashion.

So thermal generation stays at 100% (or whatever), but electrical generation output can be dropped.

It just doesn't make any sense to use reliable nuclear as the "backup" to unreliable renewables.

Because this "backup" is already CO2 free. It is also reliable. And cheap to run. So just run it all the time (nuclear tends to have >90% capacity factor).

You then simply don't need the "primary".

Otherwise you might as well say a teaspoon (or whatever) of water has as much potential fusion energy as 1 Kg U235 at a fraction of the price. ;-)

Here's why.

The Sun transforms hydrogen into helium. But that's a fairly complex chain and nobody in the industry or academia is trying to replicate that.

When people talk about fusion, here's [1] the reactions they are considering.

The best yielding fusion reaction is deuterium-tritium and deuterium-helium3 [1]. Tritium and helium-3 virtually don't occur naturally on Earth, and deuterium is very rare, at about 0.02% of the hydrogen. A teaspoon of water contains about 0.5 grams of hydrogen, and out of that about 0.0001 grams of deuterium. Let's say that someone magically brings the necessary tritium or helium-3. How does that compare with 1 gram of U235?

The fission of 1 nucleus of U235 yields about 190 MeV of energy. 1 MeV is one megaelectronvolt, and is a unit of energy. It does not matter how it translates into joules or watt-hours. It is the unit used when talking about fission and fusion. So, 235 nucleons produce 190 MeV, which is about 0.8 MeV per nucleon.

The two reactions mentioned involve 5 nucleons and yield about 18 MeV, which means 3.6 MeV per nucleon or 4.5 times more per nucleon than U235.

So, even if all the hydrogen in the one teaspoon of water was Deuterium and Tritium, in the correct ratios to do the fusion, we'd get only 4.5 times more energy than from one gram of U235. In reality, from one teaspoon of water we'd extract a very tiny amount of deuterium that's usable, and we'd need to breed Tritium or Helium-3 separately. By the way, separating deuterium from water is a very expensive process. The Nazis tried to do it during WW2, and they were doing it in Norway. Once the British special forces destroyed the plant, the Nazis could not restart the heavy water production, and their atomic project basically stopped then and there.

[1] https://en.wikipedia.org/wiki/Nuclear_fusion#Criteria_and_ca...

- More energy

- Energy diversification

That includes nuclear, solar, and even more fossil fuels as we wean ourselves off of them.

Writing off any form of energy is ideological, not practical.

I highly doubt this

And wind and especially solar have more economies of scale and materials research to make them even cheaper.

This comes from a LFTR fanboy. Boy howdy do I wish economical nuclear existed. But 6x as expensive? That ain't all red tape.

I think of course that LFTR has a path to cheaper nuclear with breeding and near waste elimination, full fuel use, safety, and scalability. But I don't think it will ever beat solar, especially once mature multifunction silicon perovskite cells or something like that and salt water batteries develop.

I hope to be proven wrong.nyclest power is so cool.

If we embarked on a sustained plan to invest in nuclear the way we have in solar and wind, nuclear's all-in cost would be far cheaper. I guarantee it.

Nukes might make sense on the moon.

Even if you could design a reactor that itself can be mass produced at that scale, you still need to do the same with selecting and getting environmental and public safety approval for installation sites and production, transportation, and disposal of the fuel and waste.

I'm not against nuclear from a technological perspective, but I just don't see it being economically competitive with effectively printable devices like solar and batteries given the current direction of the cost curves on each.

[0] https://en.wikipedia.org/wiki/Nuclear_power_in_China

Until the subsidy is repealed and taxpayers stops insuring it, the industry's frequent claims of its own safety ring kind of hollow.

It's particularly galling to see them cynically demand that safety regulations be watered down to bring down costs while the act still exists. Imagine if we made taxpayers responsible for cleaning up oil spills.

This wasn't just due to regulatory influence, it was also due to economies of scale. But the two are related, more regulation results in fewer builds. Fewer builds reduces economies of scale and thus increases costs. Which results in even fewer nuclear builds, and so on.

> (economies of scale)

Why do you blame economies of scale? The paper doesn't say that, afaict.

Also they say, "increased environmental and safety regulation ... may have led to cost increases", which does not sound conclusive.

Also, I think we really need to be talking about lifetime cost, including construction, operation, and decommissioning. In many things, spending more up front reduces later costs.

https://ourworldindata.org/grapher/solar-energy-consumption

However, we have a number of companies working on building reactors in factories. Rolls-Royce for example is talking to Ukraine to upgrade some of their old (not sure if already decommissioned) coal plants to nuclear with small, factory-built nuclear reactors.

For the same reason gas power plants and hydroelectric power plants are quoted in MW units, and not on the size of their fuel tanks or reservoir volume (converted to MWh as appropriate): it's the most important number for balancing the grid. If you have 90 GW of power demand on the grid at a given moment, you need 90 GW of power generation on the grid at that same moment (simplifying a bit, since transmission constraints mean you also need some of that power generation to be at specific places).

Which means they're irrelevant to the idea of grid scale energy storage, because they don't meaningfully store anything.

How does it feel when the Overton windows moves while nuclear is stuck in the past?

https://en.wikipedia.org/wiki/Overton_window

Modular reactors are the solution to not having enough capital or a long enough timeframe to launch and fund megaprojects at a pace that creates economies of scale anymore, which is exactly the US problem.

That's going to be tough: What happens if the day comes and they don't yet know? They can't just approve it, so just deny it?

Various agencies are constantly missing FOIA deadlines, and often the only way to get them to actually do the jobs they are legally required to do is to sue them in court, asking for both the information and to have court costs covered.

Presumably, for a regulatory agency to be held to a deadline, they would need to outline up front (or with reasonable notice) all of the things they would need to know and the inspections they would have to make. Those time tables would have to be defined early on.

This is where the idea breaks down.

    How does a regulator devise a fixed schedule to regulate a novel technology?

    How do you hold government employees accountable without upsetting powerful interests like politicians and unions, or get staffing funded properly on demand?

    How do you even get the government to hold itself accountable on something like this when the DOD can't even *complete a clean audit*?

I'm not sure we are 'winging it' at all, or doing badly. It may just be an irreduceable problem.

Proponents of a primarily solar + wind grid are betting on a breakthrough in energy storage. If that breakthrough does not transpire, we'll either have to give up on stopping carbon emissions or use nuclear power.

1. https://www.researchgate.net/figure/Overnight-Construction-C...

There's a reason why plans for a primarily renewable grid assume that compressed air, synthetic ammonia, giant flywheels, or something else will provide storage for orders of magnitude cheaper than batteries: because existing storage systems aren't capable of meeting the storage demands of intermittent generation. Will one of these systems deliver a storage breakthrough? Maybe. But it's not wise to bet the future of your electrical grid on a technological breakthrough that hasn't happened yet.

1. https://en.wikipedia.org/wiki/Steam_reforming

In the 72 years since then, in what meaningful ways has "Nuclear tech" improved?

It's not cheaper to build.

It's not cheaper to operate.

It's not cheaper to dispose of the waste.

It's not cheaper to decommission.

It's not faster to build.

?

What's more ridiculous than this oversight is the idea that the cost of wind, solar, or batteries is somehow never going to go up. News flash: all advanced industrial processes that depend on a global supply chain are subject to price fluctuations.

It's indeed not a lot. At a great cost. That kind of is the point. Nuclear is very costly.

Solar, wind, battery storage, and other cheap alternatives are indeed being rolled out at a plural orders of magnitude larger scale.

China also builds nuclear reactors, and we can't fall behind them. I cannot abide an SMR gap.

I, uh, have some uncomfortable news for you.

China are currently building 22 nuclear reactors [1]

China installed 230GW of solar and wind in 2023 [2]

China has over 40,000kms of High Speed Rail, and continues to expand [3]

By any measure, you're falling way behind them.

[1] https://www.economist.com/china/2023/11/30/china-is-building...

[2] https://www.asiafinancial.com/china-seen-installing-230-gw-o...

[3] https://www.statista.com/topics/7534/high-speed-rail-in-chin...

In other words, their CO2 emissions are set for structural decline simply by the amount of renewables being built. China is way ahead of the west.

https://theguardian.com/business/2023/nov/13/chinas-carbon-e...